Starting two-stroke internal-combustion engines.



- T. REUTER. STARTING TWO-STROKE iN ERNAL COMBUSTION ENGINES.

APr ucmoN min JAN. 9. mi 1,172,389.

Patented Feb. 22, 1916;

BROS. DIESEL ENGINE COMPANY, OF ST. LOUIS, MISSOURI,

A CORPORATION OF MISSOURI.

STARTING TWO-STROKE INTERNAL-COMBUSTION ENGINES.

Application filed Ianuaryl), 1911.

To all w ham it may concern:

Be it known that L'Tnnonon Rnu'rnn, engineer, a citizenv of the SwissRepublic, residing at :24; Obere \Vielandstrasse, -Winterthur,Switzerland, have invented certain new and useful Improvements inStarting Two-Stroke Internalombustion Engines; and I do hereby declare afull, clear, and exact description of the invention, such as will enableothers skilled in the-art to which it appcrtains to make and use thesame.

This invention is an improvement in the method of operating internalcombustion motors and more especially in the method of startingtwo-stroke motors in operation by means of fluid pressure, such, forexample, as compressed air suitably introduced into the motor cylinder.In the ordinary mode of starting motors in this way the expansion of thepressure fluid produces a re duction of the cylinder temperature towardand at the end of the expansion stroke, and upon the followingcompression stroke such temperature loss is not sufiiciently overcome toinsure reliable ignition of the initial fuel charges, this beingespecially the case where ignition takes place by the temperature 0compression of air or gas in the cylinder and also when the scavengingof the cylinder has imperfect.

been omitted or is The object of the present lIlVQlltlOIh-lS to insurereliability of ignition under all circumstances, by means of the methoddiagrammatically indicated in the drawing forming part hereof. Assumingthe motor receives a compressed air-charge from point 1 to point 2, theexansion to commence irom point 2. Now say the expansion is interruptedat point 3, for instance by opening a valve, piston sli e, or the like,equalization of pressure will be established with the exterior, thispressure equalization taking place, for example, at point l. This willtakeplace sooner or later according to the extent of the valve opening.Suction then begins -from point l by the piston traveling from thispoint The suction may take place through a special valve or through thevalve serving or establishing the pressure equalization. From oint 5 topoint 6 the piston travelsover the exhaust ports and upon the returnstroke of the piston compression commences at point 5 and reaches itsmaximum at point 1. As-

Specifitation of Letters Patent.

the following to be to point 5.

Patented Feb. 22, 1316.

Serial No. 601,718.

suming for instance the temperature of the incoming compressed air to be200 C. and its pressure to amount to 35 atmospheres. Thls condition ofthe starting air would correspond to point 2 in the diagram. EX- pansionnow following to the end of the stroke along the dotted line 2 to 5, asin the ordinary case, the temperature at the end of the expansion isabout 50 C. If no or insufficient scavenging is effected whereby thiscold air is not removed, the charge-subsequently compressed will notattain the required ignition temperature, thereby rendering ignitionquite impossible. According to the present invention, however, theexpansion is interrupted at point 3, as above stated, and equalizationof pressure is established at point 4. During this pressure equalizationto atmospheric pressure the temperature falls considerably less thanduring a regular expansion. From point 4: to point 5 the piston draws inair from the outside, which air may be cold, z'. e., atmospherictemperature, preliminarily heated or hot. In the place of air anyindifferent gas may be introduced. At the end of the stroke the cylindercontains a quantity of air- 0 considerably higher temperature than wouldbe the case in the event of an uninterrupte expansion without the use ofthe present method. The ignition temperature during the subsequentcompression can therefore be attained with ease and a regular startingis consequently insured. On ignition taking place normal working may beemployed.

The admission of the compressed air may be regulated at will. As aresult of the suction stroke from point 4 to point 5 the cylinder willcontain sufiieient air for combustion and ignition will take placeevenif littleor no compressed air enters the cylinder.

I claim,

1. A method of starting combustion motors by compressed air whichconsists in admitting compressed air to the motor cylinder interruptingthe expansion of such air therein before the end of the expansion strokeand prior to the point at which products of combustion are releasedduring normal operation, whereby to prevent excessive decrease oftemperature and thereupon introducing and compressing a gas in thecylinder for combustion.

2. A method of starting combustion motors which comprises admitting a.com-

pressed fluid to the motor cylinder, allowing the same to expand againstthe piston, in--' terrupting' such expansion before the end of theexpansion stroke and prior to the point at which products of combustionare released during normal operation, whereby to prevent excessivedecrease of temperature in the cylinder, and in a following strokeadniitting and compressing in such. cylinder the material for thecombustion charge.

3. A method of starting two stroke combustion motors which comprisesexpanding a compressed fluid in the motor cylinder, i.n terrupting suchexpansion before the end of the expansion stroke, admitting a Warmer gasto the cylinder during the remainder of such stroke,- and in a followingcompression 1,17a,ese

THEODOR REUTER.

Witnesses CARL GUBLER, Auens'r Rlvnoo.

